ESCA investigation of V2O5+TiO2 catalysts for the vapour phase oxidation of alkylpyridines

摘要: Sensitivity factors for the quantitative analysis of vanadium- and titanium-oxide mixtures by ESCA have been determined from calibration curves various V2O5+TiO2 mixtures.Sintered Ti(VO3)4 sintered powder V2O5 TiO2 in ratios yielded a higher vanadium content than bulk composition; this is caused particles being embedded matrix V2O5. The unsintered mixtures, on other hand, gave atom good agreement with composition.The V 2p, Ti 2p O 1s electron binding energies half widths were measured oxides oxide both unsintered. lower non-stoichiometric at surface.The catalysts used oxidation alkylpyridines only reduced thin surface layer. was partially to valence states while unchanged, as signals. degree reduction varied throughout catalyst bed, highest nearest reactor inlet. It strongly dependent upon reaction temperature maximum obtained 455°C, same which gives selectivity. Surface compositional changes V, O, participating catalysis, observed all used.